Consumers buy sunglasses, be sure to note the following:
1, we must first know the purpose of their own choosing sunglasses
We know that different types of sunglasses for different occasions and people. We want to buy sunglasses must first determine the purpose of the optional shade, or with clothing for decoration? In addition to shading, anti-UV function requirements? Are there any special requirements the safety performance of the lens? Only clear these aims, combined with style and wear the actual effect of the face, I can buy the right pair of sunglasses.
2, we must learn to read the product identification
Not all sunglasses have anti-ultraviolet function, a meet the basic requirements of the standard sunglasses can only say that, while blocking the glare is not through more UV light. Pair of sunglasses can block light and not block the same amount of UV light on the wearer, would be acceptable to not wear sunglasses more UV light (wear sunglasses, will be reduced into the human eye flux, resulting in wearers pupil increase). Sales counter of the store sunglasses, lenses, logo or packaging are generally obvious uv380, uv400 and other similar signs, as in the clothing on the same fabric composition label, consumers must purchase carefully.
(1) the identity of the anti-UV function
A pair of sunglasses with anti-ultraviolet function, we can not distinguish with the naked eye, factory express commitment to consumers in the only reference to the protection sunglasses, we can see the positive in a number of product labels and glasses such as: "100% anti-UV", "UV400", "block all UV, anti-ultraviolet express identity. UV is the sun's rays of wavelengths between 200nm ~ 400nm, including three categories: UVA wavelength of 315nm ~ 400nm, UVB, wavelength of 280nm ~ 315nm, UVC, wavelength is 200nm ~ 280nm. The ultraviolet rays of the sun's rays reach the earth's surface (290nm ~ 2000nm) accounted for about 13%, which accounted for 97% of UVA, UVB, accounting for 3%, UVC is close to 0. UV damage to the human eye depends on the wavelength of the UV radiation time and radiation intensity and the strength of self-defense mechanism of the human eye, the cornea, the lens is the most common ocular tissue damage by ultraviolet solar keratitis and corneal endothelial damage daylight cataract with the most relevant eye diseases. In order to protect the health of the eye, you can choose the sunglasses lenses made with anti-UV function, try to eliminate the ultraviolet below 400nm.
(2) The identity of the safety performance
Safety performance sunglasses, the lens produced materials such as PC tablets, TAC lenses impact on the label and instructions are often marked with "shock resistance" by the U.S. FDA, "consistent with the highest standards of Europe and the United States "If the product can reach the label requirements, motorcycle riders, drivers and other special requirements of consumers is a good choice for security. Commitment on the product label, consumers should learn to protect themselves, the label or instructions or save, or allow businesses to indicate on the invoice, in the event of disputes, would not be for lack of evidence passive.
3, there must be to identify the basic skills of the lens intrinsic quality
(1) the degree of the lens should meet the requirements of the plain glass lens, and should not affect the vision of optical flaws. Simple method for the identification of sunglasses can be placed in front of a distant target viewed through the lens, such as window frames or door frames, and then the glasses up and down to move back and forth, the goal should not swing and wave-shaped deformation.
(2) The color of the lens can not be partial, the color of the surrounding environment without distortion, sharp edges of objects has the ability to effectively identify the different color lights. The choice of lens color depth, depending on the desired place of the color of the lens will affect the shading effect of different light sources and occasions. Make the sunglasses can effectively block the Xia Jiqiang light, the color of the glasses due to sufficient depth, but the bike or car, do not select the lens color is too dark.
